If you were to discover that a fundamental component of human biology has survived virtually intact for the past 25 million years, you'd probably be quite confident in saying that it is here to stay. Such is the case for a team of Whitehead Institute scientists, whose latest research on the evolution of the human Y chromosome confirms that the Y—despite arguments to the contrary—has a long, healthy future ahead of it. Proponents of the so-called “rotting Y” theory have been predicting the eventual extinction of the Y chromosome since it was first discovered that the Y has lost hundreds of genes over the past 300 million years. The rotting Y theorists have assumed this trend is ongoing, concluding that inevitably, the Y will one day be utterly devoid of its genetic content. Over the past decade, Whitehead Institute Director Dr. David Page and his lab have steadily been churning out research that should have permanently debunked the rotting Y theory, but to no avail. "For the past 10 years, the one dominant storyline in public discourse about the Y is that it is disappearing," says Dr. Page. "Putting aside the question of whether this ever had a sound scientific basis, the story went viral—fast—and has stayed viral. I can't give a talk without being asked about the disappearing Y. This idea has been so pervasive that it has kept us from moving on to address the really important questions about the Y." To Dr. Page, this latest research represents checkmate in the chess match he's been drawn into against the "rotting Y" theorists. Members of his lab have dealt their fatal blow by sequencing the Y chromosome of the rhesus macaque—an Old World monkey whose evolutionary path diverged from that of humans some 25 million years ago—and comparing it with the sequences of the human and chimpanzee Y chromosomes.